eventsource

README

eventsource

eventsource provides server-sent events for net/http server.

Usage

SSE with default options

package main

import (
    "gopkg.in/antage/eventsource.v1"
    "log"
    "net/http"
    "strconv"
    "time"
)

func main() {
    es := eventsource.New(nil, nil)
    defer es.Close()
    http.Handle("/events", es)
    go func() {
        id := 1
        for {
            es.SendEventMessage("tick", "tick-event", strconv.Itoa(id))
            id++
            time.Sleep(2 * time.Second)
        }
    }()
    log.Fatal(http.ListenAndServe(":8080", nil))
}

SSE with custom options

package main

import (
    "gopkg.in/antage/eventsource.v1"
    "log"
    "net/http"
    "strconv"
    "time"
)

func main() {
    es := eventsource.New(
        &eventsource.Settings{
            Timeout: 5 * time.Second,
            CloseOnTimeout: false,
            IdleTimeout: 30 * time.Minute,
        }, nil)
    es.SendRetryMessage(3 * time.Second)
    defer es.Close()
    http.Handle("/events", es)
    go func() {
        id := 1
        for {
            es.SendEventMessage("tick", "tick-event", strconv.Itoa(id))
            id++
            time.Sleep(2 * time.Second)
        }
    }()
    log.Fatal(http.ListenAndServe(":8080", nil))
}

SSE with custom HTTP headers

package main

import (
    "gopkg.in/antage/eventsource.v1"
    "log"
    "net/http"
    "strconv"
    "time"
)

func main() {
    es := eventsource.New(
        eventsource.DefaultSettings(),
        func(req *http.Request) [][]byte {
            return [][]byte{
                []byte("X-Accel-Buffering: no"),
                []byte("Access-Control-Allow-Origin: *"),
            }
        },
    )
    defer es.Close()
    http.Handle("/events", es)
    go func() {
        id := 1
        for {
            es.SendEventMessage("tick", "tick-event", strconv.Itoa(id))
            id++
            time.Sleep(2 * time.Second)
        }
    }()
    log.Fatal(http.ListenAndServe(":8080", nil))
}

Documentation

Overview

Package http provides server-sent events for net/http server.

Example:

package main

import (
    "gopkg.in/antage/eventsource.v1"
    "log"
    "net/http"
    "strconv"
    "time"
)

func main() {
    es := eventsource.New(nil, nil)
    defer es.Close()
    http.Handle("/events", es)
    go func() {
        id := 1
        for {
            es.SendEventMessage("tick", "tick-event", strconv.Itoa(id))
            id++
            time.Sleep(2 * time.Second)
        }
    }()
    log.Fatal(http.ListenAndServe(":8080", nil))
}

Index

• type EventSource
  • func New(settings *Settings, customHeadersFunc func(*http.Request) [][]byte) EventSource
• type Settings
  • func DefaultSettings() *Settings

Types

type EventSource

type EventSource interface {
	// it should implement ServerHTTP method
	http.Handler

	// send message to all consumers
	SendEventMessage(data, event, id string)
	// send retry message to all consumers
	SendRetryMessage(duration time.Duration)

	SendMessageToClient(clientID, data, event, id string)
	SendRetryMessageToClient(clientID string, duration time.Duration)

	// consumers count
	ConsumersCount() int

	// close and clear all consumers
	Close()
}

EventSource interface provides methods for sending messages and closing all connections.

func New

func New(settings *Settings, customHeadersFunc func(*http.Request) [][]byte) EventSource

New creates new EventSource instance.

type Settings

type Settings struct {
	// SetTimeout sets the write timeout for individual messages. The
	// default is 2 seconds.
	Timeout time.Duration

	// CloseOnTimeout sets whether a write timeout should close the
	// connection or just drop the message.
	//
	// If the connection gets closed on a timeout, it's the client's
	// responsibility to re-establish a connection. If the connection
	// doesn't get closed, messages might get sent to a potentially dead
	// client.
	//
	// The default is true.
	CloseOnTimeout bool

	// Sets the timeout for an idle connection. The default is 30 minutes.
	IdleTimeout time.Duration

	// Gzip sets whether to use gzip Content-Encoding for clients which
	// support it.
	//
	// The default is false.
	Gzip bool

	ClientIDFunc func(*http.Request) string
}

func DefaultSettings

func DefaultSettings() *Settings